The present disclosure relates to semiconductor fabrication, and more specifically, to a sensor for an integrated circuit (IC) structure for moisture and chip integrity monitoring having interdigitated conductive elements.
During semiconductor fabrication and during IC packaging, monitoring of chip package integrity is an important part of the process. IC chips are formed on a semiconductor wafer and separated into individual chips by cutting that can damage the chips. Any moisture or cracks/defects in an IC structure can lead to chip failures and/or performance degradation. Typically, a sensor including conductive perimeter lines (e.g., 2 perimeter lines) are provided around a periphery of a chip to monitor chip integrity. In use, the conductive perimeter lines can be used to measure changes in leakage that indicate the presence of moisture, and/or changes in resistance that indicate the presence of cracks or other physical defects. As current technology continues to scale to smaller dimensions, e.g., 22 nm and beyond, the sensor dimensions also are reduced, resulting in increased resistance thereof. With advancing minimum ground rule dimensions, the very long perimeter lines are becoming too high in resistance to be useful. To address this issue, the perimeter lines are being made wider, which also requires wider spacing that makes the measurements of leakage less sensitive.